An amplifier will only 'boost' what is available, if nothing available it will boost nothing, if crap is available it will boost crap.
If getting break up, check what is between the aerial and the transmitter, trees, especially wet ones, will block the signal.
Hight of aerial can also have an effect but sometimes not in the way expected, have had it where by lowering the aerial it has picked up a cleaner signal.
Also check all connections are clean and good.
ps. I also have a log periodic aerial but sometimes it is just impossible to get a signal, depends on location.